The present invention relates to apparatus and methods for reducing drag caused by wind loads on appurtenances mounted on communication towers.
Communication tower appurtenances, such as communication antennas mounted on tall communication towers are structures that are typically attached to brackets or to platforms attached to the towers. Typical communication antennas are flat, which means that they can experience substantial wind loading when the flat surfaces are normal to the wind direction. When exposed to high winds, such antennas, and other antenna tower appurtenances, experience high wind loads.
Wind loading governs the design of all communication tower appurtenances as per ANSI/TIA-222-G (Effective Jan. 1, 2006), which is the commonly accepted standard.
It would be desirable to have apparatus and methods for reducing drag resulting from wind loads on communication tower appurtenances, such as communication antennas exposed to winds.
Table 1 from the ANSI/TIA-222-G Code shows force coefficients (Ca) for appurtenances on communication towers.